Just to say that I grew up around boats and I´ve been working around boats for the last 15 years or so. The OP could have showed me any ONE of those shots and I would know what they are and what the man is doing. On the color one you can even see the reflection of the hull and keel of another boat.

I like those shots and the sharpness and rendering of the Tammy. Even though I don´t own neither the Tamron nor the Nikkor 70-300, my take from the hundreds of threads is that they each have their own strenghs and they are both pretty good for consumer zooms.

Yup, I really don't think anyone with a knowledge of boats or someone viewing the photo on a surveyor website will be guessing he's looking at ice-sculpture.

I've got shots of a piano tuner somewhere that, out of context, might be hard to identify unless you know what a piano-tuning lever looks like.

Overall I don't see an optical deficiency in the Tamron as I do with the Nikon. Perhaps the Nikon's advantage could be in AF speed, though I'd have to a hold of another 70-300vr to test.

Here's a sample (crop) at 70mm again with D800...

This picture DOES tell a story. It says: I'm not really working at this moment and POSING for the shot!